Material with microporous crystalline walls defining a narrow size distribution of mesopores, and process for preparing same

ABSTRACT

The invention relates to a synthetic crystalline material and its use in catalytic conversion of organic compounds and as a sorbent. The crystalline material contains one or more microporous crystalline phases, having a micropore volume greater than or equal to about 0.15 cc/g distributed in channels between about 3 to about 15 Å in average diameter which is rendered accessible by a mesopore volume of greater than or equal to about 0.1 cc/g distributed in channels between about 20 to about 100 Å in average diameter. A process is also provided for preparing the crystalline material of the present invention.

This is a Continuation of application Ser. No. 08/659,645, filed Jun. 6,1996 now U.S. Pat. No. 5,849,258.

BACKGROUND OF THE INVENTION

The invention relates to a synthetic material which is particularlyuseful for processing feedstock having large organic molecules, eitheras a catalyst or as a sorbent.

The processing of large organic molecule-containing feedstocks such asheavy hydrocarbons, fine chemicals, pharmaceutical products and the likeinvolving catalysts or adsorbents is typically inefficient and expensivedue to the lack of catalyst materials with appropriate qualities. Asignificant limitation on conventionally known active agents is the lackof sufficient pores of appropriate size in the catalyst or adsorbent tocarry out the desired process.

Typically, heavy hydrocarbons are processed using amorphous materialshaving pore volumes lower than 0.1 cc/g, which pore volume isdistributed over a wide range of pore diameters, typically rangingbetween 20 to 1,000 angstrom (Å) in diameter. Due to the large range andhigh upper end of the pore diameter of this material, the pore volume islower than would be desirable. Furthermore, these materials possesslow-activity sites where activity is defined in terms of number ofmolecules converted per unit of time, thereby limiting theireffectiveness as promoters in conversion to desirable products.

Due to the foregoing limitations, heavy hydrocarbons are occasionallyprocessed using zeolite catalysts which are not ideal due to the porediameter formed in crystalline microporous aluminosilicates such aszeolite. Because of the small pore diameter, only active sites on theparticle exterior of the zeolite are useful for processing such heavyhydrocarbons. This results in the use of large quantities of thezeolite, thereby significantly increasing the catalyst cost involvedwith the process, and decreasing the profitability of same.

Attempts have been made to improve the accessibility to largehydrocarbons of the active sites in a zeolite material. One method whichhas been industrially applied has been the dealumination of thematerial, for example by steam or contact with SiCl₄. By extractingaluminum from the zeolite framework, a portion of the crystal structurecollapses giving rise to holes ranging in diameter from 10 Å to 1,000 Å.Although this procedure does provide some degree of larger pore volumein zeolites, several disadvantages are inherent. First, severalpost-synthesis steps are required, which result in the waste of aportion of the original starting zeolite material, thereby making thesynthesis process more complicated and expensive. In addition, amorphousalumina particles resulting from the extraction process are left on thesurface on the mesoporous channels, hindering or even blocking thediffusion of reactants and products. Further, this procedure does notselectively generate pores of a particular desired size. Rather, arandom distribution of large pores are generated, most of which arelarger than 100 Å in diameter. Because of this, dealuminated zeoliteshave limited use in catalytic processes that, based on size exclusionprinciples, must essentially yield a desired large organic product.

Available sorbents for separation of large molecules from feedstocksalso have important technological limitations. They are constituted byamorphous materials, with low density of sorption sites.

It is clear, therefore, that the need remains for an improved material,for use either as a catalyst or as a sorbent, in processing, convertingand/or purifying feedstocks having large organic molecules such as heavyhydrocarbons and the like.

It is therefore the primary object of the present invention to provide asynthetic material having microporous crystalline walls, accessiblethrough a high volume of mesoporous channels of desired and controlledpore diameter sizes and distributions.

It is a further object of the present invention to provide a process forpreparing the material of the present invention wherein the material hasmicroporous crystalline walls having micropore sized pore volume and isprovided with a high mesopore sized pore volume in a narrow pore sizedistribution.

It is still another object of the present invention to provide a processfor treating a feedstock having large organic molecules with thematerial of the present invention used as a catalyst so as to provideconversion and transformation of the feedstock into more valuableproducts, at high rates of conversion, and with high selectivity.

It is still another object of the present invention to provide a processfor purification of a mixture of organic compounds so as to selectivelyremove one or more components from this mixture by adsorption onto thematerial of the present invention.

Other objects and advantages of the present invention will appearhereinbelow.

SUMMARY OF THE INVENTION

In accordance with the invention, the foregoing objects and advantagesare readily attained.

According to the invention, a material is provided for processingfeedstocks including large organic molecules either as a catalyst or asa sorbent. The material comprises a crystalline material having at leastone microporous crystalline phase having a micropore volume of at leastabout 0.15 cc/g distributed in channels between about 3 to about 15 Å inaverage diameter, and having a mesopore volume of at least about 0.1cc/g distributed in channels between about 20 to about 100 Å in averagediameter, whereby said mesopore volume renders said micropore volumeaccessible.

In further accordance with the invention, a process is provided forpreparing the material of the present invention, comprising the steps ofproviding a suspension of nuclei of a microporous crystalline molecularsieve material in an aqueous media; mixing the suspension with a watersoluble tensoactive organic compound to provide a mixture of the nucleiand micelles of the tensoactive organic compound in solution; inducingaggregation of the nuclei around the micelles so as to provide a solidmaterial having the organic compound dispersed therein; and extractingthe organic compound from the solid material to provide a crystallinemolecular sieve material having a micropore volume greater than or equalto about 0.15 cc/g distributed in channels about 3 to about 15 Å inaverage diameter, and having a mesopore volume of at least about 0.1cc/g distributed in channels about 20 Å to about 100 Å in averagediameter.

The material according to the present invention is advantageous in thata catalyst is provided for use in conversion and transformation of heavyhydrocarbon and other feedstocks which include large organic moleculeswherein mesopore-sized pore volumes are provided in the catalystmaterial so as to provide access for the large organic molecules to theinterior sites of the catalyst material. Further advantageously, thecatalyst and the process for preparing same in accordance with thepresent invention result in a narrow size distribution of the largermesopores, thereby providing increased pore volume and improved accessto interior portions of the catalyst material.

The material according to the present invention is also advantageous foruse in purification of organic feedstocks, in which case one or morecomponents from the feed are separated by being sorbed within themesopores of the material of the present invention. These components canthen be recovered by extracting them from the material of the presentinvention with a heat or solvent treatment. Alternatively, thesecomponents can be safely disposed, while sorbed within the material ofthe present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A detailed description of preferred embodiments of the inventionfollows, with reference to the attached drawings, wherein:

FIG. 1 is the N₂ desorption isotherm for the product of Example 1;

FIG. 2 is a derivative of the N₂ desorption volume as a function of porediameter for the product of Example 1, showing its size distribution ofmesopores;

FIG. 3 is the N₂ desorption isotherm for the product of Example 2;

FIG. 4 is a derivative of the N₂ desorption volume as a function of porediameter for the product of Example 2, showing its size distribution ofmesopores;

FIG. 5 is the N₂ desorption isotherm for a commercial steam dealuminatedzeolite Y;

FIG. 6 is a derivative of the N₂ desorption volume as a function of porediameter for a commercial steam dealuminated zeolite Y, showing its sizedistribution of meso and macropores.

FIG. 7 is the N₂ description isotherm for the product of Example 4; and

FIG. 8 is a derivative of the N₂ description volume as a function ofpore diameter for the product of Example 4, showing its sizedistribution of mesopores.

DETAILED DESCRIPTION

The invention relates to a material and process for preparing samewherein nuclei of a crystalline microporous molecular sieve material areaggregated such that a narrow size distribution of mesopore-sized porevolume is provided.

According to the invention, the material comprises a crystallinemicroporous molecular sieve material which also has a narrow sizedistribution of larger mesopore sized pore volume. The molecular sievematerial of the present invention preferably includes a micropore-sizeddistribution having pore sizes between about 3 Å to about 15 Å, and themicropore-sized pore volume is preferably at least about 0.15 cc/g. Themesopore-sized pore volume preferably has a pore size distribution ofbetween about 20 Å to about 100 Å, and the mesopore-sized pore volume ispreferably at least about 0.1 cc/g.

The crystalline microporous walls in the material of the presentinvention are further characterized by an x-ray diffraction patternwhich exhibits at least two lines at d-spacings of less than 15 Å, bythe presence of an absorption band between 540 cm⁻¹ and 750 cm⁻¹ in aninfrared spectrum and/or by an ion exchange capacity higher than 0.05milliequivalents per gram of material on a dry basis.

The narrow mesopore size distribution in the material of the presentinvention is further characterized by a desorption isotherm having asharp inflection point at partial pressures P/P₀ (nitrogen or argon) ofbetween about 0.05 to about 0.8, where P/P₀ is a ratio of the pressureat which the sorbate gas desorbs (P) and the vapor pressure of theliquefied sorbate gas (P₀).

In accordance with the invention, the nuclei of the microporouscrystalline molecular sieve material may suitably be selected from thegroup consisting of metalosilicate, zeolite, aluminophosphate,metaloaluminophosphate, silicoaluminophosphate,metalosilicoaluminophosphate and mixtures thereof. These materials areparticularly desirable because of their microporous molecular sievestructure which provides particularly useful microporous crystallinewalls with desirably active sites, which microporous crystalline wallsare rendered accessible to larger sized organic molecules by a largevolume of mesopore-sized channels which the material is provided with inaccordance with the invention.

The material of the present invention is prepared by mixing a suspensionof nuclei of the desired microporous crystalline molecular sievematerial in an aqueous media with an organic compound having tensoactiveproperties selected to provide the desired mesopore size and sizedistribution as will be discussed further below. The mixture ofsuspension of nuclei and organic compound is then subjected toappropriate synthesis conditions so as to induce aggregation of thenuclei in the mixture. According to the invention, specific nuclei andorganic compound are selected and mixed, so as to promote interactionand intimate contact between the nuclei and micelles of the organiccompound. This results, advantageously, in the nuclei condensing aroundmicelles of the organic compound resulting in the formation of a solidmaterial having the crystalline molecular sieve material formed aroundthe organic compound.

In further accordance with the process of the present invention, thesolid material of crystalline molecular sieve material formed aroundorganic compound is then further treated so as to extract the organiccompound, for example by calcination or solvent extraction, therebygenerating mesopore-sized void volume in the spaces formerly occupied bythe organic compound. Advantageously, the organic compound can suitablybe selected according to the invention so as to provide the mesoporevoid volume with a narrow size distribution of pores of between about 20Å to about 100 Å.

Nuclei of the microporous crystalline molecular sieve material maysuitably be selected from the group consisting of metalosilicate,zeolite, aluminophosphate metaloaluminophosphate,silicoaluminophosphate, and metalosilicoaluminophosphate, among others.Particularly preferable are such materials which synthesize to form acrystalline structure having the desired micropore-sized channels andactive sites with the desired strength and density for the use of thematerial of the present invention as a catalyst or as a sorbent in aparticular application.

The organic compound used to generate the mesopore-size pore volume ispreferably selected, based upon the microporous crystalline molecularsieve material being used, so as to provide micelles of the organiccompound in water which under synthesis conditions will interact andresult in intimate contact with the microporous crystalline molecularsieve nuclei. Within this broad range of suitable materials, certaincationic surfactant such as quaternary ammonium salts, anionicsurfactant such as alkylbenzesulfonates, alkyl sulfates,alkanesulfonates, hydroxyalkyl sulfonates, alpha-olefinsulfonate, alkylether sulfate, petroleum sulfonate, phosphate esters, soaps, or acylatedamino acids, non-ionic surfactant such as ethoxylated alcohols,ethoxylated alkyl alkylphenols, ethoxylated acids, fatty acidalkanolamides, ethoxylated alkanolamides, ethoxylated amines, amineoxides, derivatives of saccharaides, or polyalcohols and amphotericsurfactant such as carboxybetaines, amino acids or lecithin aresuitable.

As set forth above, it is desirable in accordance with the presentinvention to promote attractive interactions between the microporouscrystalline nuclei and the organic compound in solution so that thesematerials are in intimate contact during nuclei aggregation. The desiredinteraction can be provided, for example, by either or both ofelectrostatic forces and van der Waal's forces. Numerous organiccompounds or molecules may suitably be used to promote the desiredinteraction including but not limited to those set forth above.

It has been found in accordance with the present invention that certaincombinations of nuclei and organic compound have enhanced attractiveinteraction at certain synthesis conditions, especially the solution pHat which nucleation is carried out. For example, when cationicsurfactant are dissolved in an aqueous phase, they are partially tototally dissociated, giving rise to cationic organic species thatpreferentially interact with a suspension of inorganic negativelycharged material such as, for example, metalosilicate or zeolite nucleiat a pH higher than 6. As another example, anionic surfactant give riseto organic anions in solution which preferentially interact with asuspension of inorganic nuclei positively charged, such as, for example,aluminophosphates metaloaluminophosphates, silicoaluminophosphatesand/or metalosilicoaluminophosphate at pH lower than 7.

Other factors which influence the desired attractive interaction betweenthe nuclei and organic compound in solution are solution temperatureslower than 100° C., and/or inorganic salts that intercalate between theorganic tensoactive ion and the inorganic nuclei, when they have thesame charge in solution. In accordance with a preferred embodiment ofthe invention, nuclei of a microporous metalosilicate are provided bypreparing them according to the prior art from inorganic salts and/orcolloidal precursors. More preferably, nuclei of the zeolite faujasiteare provided and they are preferably mixed with a basic solution (havinga pH greater than 7) containing 1 or more cationic and/or non-ionicsurfactant. According to the invention, this mixture is then preferablyaged at temperatures of between 20° C. to about 100° C. for at least onehour to promote the aggregation of the zeolite nuclei around themicelles of the tensoactive organic compound.

In accordance with the invention, the resulting solid is then washed inwater and dried, and the tensoactive organic compound is then extractedpreferably by calcination in air so as to provide the solidifiedcrystalline microporous faujasite with a mesopore-sized pore volumehaving the desired narrow pore-sized distribution. The material soprepared in accordance with the invention is particularly useful as acatalyst or a sorbent because the zeolitic sites are accessible throughthe larger mesopore pore volume, and sites are provided which may betailored, for example, through the use of other metals and the like, toprovide a desired activity.

A further alternative embodiment of the process of the present inventioninvolves synthesis of the material using metalophosphates, especiallyaluminophosphate or silicoaluminophosphate nuclei.

In accordance with this process, the desired nuclei are mixed in asolution preferably having neutral or acid pH, preferably a pH less thanor equal to 5 with one or more anionic and/or non-ionic surfactant. Thismixture is then aged at temperatures of between about 20° C. to about100° C. for at least one hour to promote aggregation of themetalophosphate nuclei around the surfactant micelles. As with the aboveprocess, the resulting solid is then washed in water and dried, and theorganic compound is then extracted from the solid so as to provide thedesired mesopore-sized pore volume.

The material of the present invention comprises a crystalline materialhaving at least one microporous crystalline phase. However, inaccordance to the process of the present invention, it has been foundthat if nucleii of a dense phase are aggregated around the micelles ofthe tensoactive organic compound, a material with a narrow distributionof mesopores, a mesopore volume of greater than or equal to 0.1 cc/g,but without micropores, is formed, as demonstrated in example 4.

It should be appreciated that the amount of mesopore-sized pore volumeprovided according to the invention depends upon the amount ofsurfactant included in the nuclei/organic compound solution. Further,the size of the mesopore-sized pores depends upon the length of thehydrophobic tail of the surfactant, with a longer tail providing alarger mesopore pore size. Thus, the amount and size of mesopore-sizedpore volume can be selectively controlled by selecting the proper amountand size of organic compound.

The amount and size of the mesopore-sized pore volume can also beselectively controlled by adding organic water-insoluble compounds tothe mixture of the inorganic nuclei and the tensoactive organiccompound. These water-insoluble compounds combine with the hydrophobictail of the surfactant, and increase the size of the micelle aroundwhich the inorganic nuclei aggregate, thus increasing the size andvolume of the resulting mesopore-sized channels in the material of thepresent invention.

As in the case of many catalysts, it may be advantageous to combine thematerial of the present invention with a matrix material that hasdesirable thermal and mechanical properties, among others. The materialof the present invention may also be combined with other materials, usedas diluents to control the amount of conversion in a given process.Examples of such materials are aluminas, silicas, silica-aluminas,magnesias, titanias, zirconias, carbons and their precursors, clays andmixtures thereof. Also, precursors to the above mentioned materials canbe used, such as colloidal silica, alumina sols, suspensions ofpseudo-bohemite, titania, or zirconia, and/or hydrosols of any of abovementioned oxides, among others. These materials may be combined with thematerial of the present invention during preparation or in apost-synthesis process. Also, these materials may be provided in part incolloidal form so as to facilitate extrusion of the bound components.

In order to confer desirable thermal and/or mechanical properties to thematerial of the present invention, it may also be advantageous toincorporate a binder material when inducing the aggregation of theinorganic microporous crystalline nuclei around the micelles of thetensoactive organic compound. Examples of such binder materials arecolloidal silica, alumina, silica-alumina, magnesia, titania, zirconiaand mixtures thereof.

The nuclei used in the preparation of the material of the presentinvention may be prepared according to the prior art, starting frominorganic salts, or by dissolving gels or powders of the desirablemicroporous crystalline molecular sieve material in either acid or basicsolutions. When prepared from inorganic salts, the latter are dissolvedin either basic, acidic, or neutral solutions, and treated attemperatures of between about 5° C. to about 200° C., for times ofbetween about 10 minutes to about 120 hours, and with or without thefurther addition of structure directing or template agents such as, forexample, mono, di, tri and tetra-alkyl amines, crown ethers and mixturesthereof.

The material of the present invention is useful as a catalyst forconversion of organic compounds, especially large hydrocarbons withmolecular sizes of about 15 Å or more. It is particularly useful forcatalyzing reactions that occur in the presence of acidic sites, inwhich the large hydrocarbon molecule is converted into products of lowermolecular weight or into more valuable isomers. Examples of suchreactions are involved in processes such as cracking, hydrocracking andisomerization. In such processes the material of the present inventionpresents various advantages over conventional catalysts. The strength ofthe acidic site can be conveniently adjusted, by selecting a convenientkind of nuclei, during preparation of the material of the presentinvention. If strong acid sites are advantageous, then nuclei ofzeolites such as, for example, X, Y, L, mordenite, beta, MFI-type orMTW-type can be used. If weaker acid sites are preferred for aparticular application, then nuclei of silicoaluminophosphates ormetaloaluminophosphates could be used. Because the material of thepresent invention has well structured crystalline walls, thedistribution of active sites throughout the mesoporous channels isuniform, and can be controlled by adjusting the composition of themicroporous crystalline nuclei during preparation of the material of thepresent invention. The activation of acidic sites in the material of thepresent invention may require the substitution of alkali metals byprotons, either through direct ion-exchange with an acid solution or byion exchange with an ammonium salt solution, followed by heat treatmentto evolve ammonia.

Another advantage of the material of the present invention is that thelarge mesopore size and volume allow large hydrocarbon molecules toeasily access the catalytically active sites located on the crystallinemicroporous walls, thereby minimizing diffusional constraints. Theimproved diffusion through channels also allows the primary productsfrom the transformation and or conversion of the large hydrocarbonmolecule to exit the material before secondary reactions can take place,thereby retarding or even avoiding the formation of undesirablesecondary products such as coke which could eventually plug the channelsor deactivate the catalytic sites on the crystalline walls of thematerial.

It may also be advantageous to incorporate into the material of thepresent invention minor amounts of metals as catalytic components,especially noble metals such as platinum, rhodium, rhenium, iridium, orGroup VIII metals such as nickel, iron and/or cobalt, or Group VI metalssuch as chromium, molybdenum and/or tungsten. These metals may bepresent in their metallic state, or as oxides, sulfides or mixturesthereof. These metals could provide the material of the presentinvention desired catalytic properties for processes such ashydrotreatment, hydroisomerization, hydrocracking, hydrogenation and/orreforming, to convert large hydrocarbon molecules into more valuableproducts.

The material of the present invention may also be advantageously used asa sorbent for the selective separation of one or more components in afeed. The narrow pore size distribution of mesopores and the large porevolume allow for the separation of components in the feed by sizeexclusion of molecules. Also, the microporous crystalline walls of thematerial of the present invention provide for sites that can be modifiedwith the incorporation of molecules that contain specific functionalgroups with affinity toward specific components in the mixture, allowingtheir separation from the feed. Examples include the incorporation ofamines to preferentially adsorb acidic components in a feed, orchelating agents that separate metal contaminations off a stream. Also,these sites on the microporous crystalline walls of the material of thepresent invention can be used to incorporate compounds that can controlthe hydrophilicity of the environment within the pores, advantageouslyallowing the separation of polar from non-polar components in a feed.

The material of the present invention may also be advantageously usedfor recuperation or abatement of metal cations in water, since itsmicroporous crystalline walls provide for a high density of ion-exchangesites, and its mesoporous channels avoid diffusional problems associatedwith accessing these sites in conventional materials.

Although the material of the present invention is useful in thetreatment of any hydrocarbon molecule, it is particularly advantageouswhen used for the treatment of large molecules that are too big to fitinto the channels of more conventional catalysts and/or sorbents. Thematerial of the present invention is especially suited for the treatmentof high boiling point hydrocarbon fractions in crude oils such asatmospheric and vacuum gas oils, high boiling point products fromprocesses such catalytic cracking, thermal cracking, lube production andthe like and non-distillable fractions from crude oil or from conversionprocesses such as residual feeds. The material of the present inventioncould also be utilized with feeds of non-petroleum origin.

The following examples further illustrate the catalyst material andprocess of the present invention.

EXAMPLE 1

This example demonstrates the preparation of a material using faujasiteX in accordance with the invention.

Initially, a suspension of faujasite X nuclei in water was prepared asfollows. A suspension (Suspension A) was formed by vigorously stirring amixture of 20.5 g of sodium silicate (29% wt SiO₂ ; 9.3% wt Na₂ O; 61.7%wt H₂ O) and 6.8 mL of a 13.4 M NaOH solution. A solution (Solution B)was prepared by dissolving 1.38 g of sodium aluminate (49.1% wt Al₂ O₃ ;27.2% Na₂ O, 23.7% H₂ O) into 8.2 mL of a 5.9 M solution of NaOH.Suspension A was added over Solution B, while stirring the latter. Afterthe addition was complete, stirring was continued for one more hour,resulting in a clear suspension of faujasite X nuclei having thefollowing composition:

    1 SiO.sub.2 :0.066 Al.sub.2 O.sub.3 :1.06 Na.sub.2 O:15.1 H.sub.2 O

This suspension was aged at room temperature for 2.7 hours, after whicha solution of 7.98 g of cetyltrimethylammonium bromide (CTAB) in 10 g ofwater was added, resulting in a suspension having the followingcomposition:

    1 SiO.sub.2 :0.066 Al.sub.2 O.sub.3 :1.06 Na.sub.2 O:0.22 CTAB:21 H.sub.2 O

This suspension was aged for 24 hours at a temperature of 80° C., andthe resulting solid was washed, dried at 100° C. for 4 hours, and thencalcined at 500° C. for 6 hours in a flow of air.

The calcined product shows an x-ray diffraction pattern having the mainstrong signals as set forth below in Table 1:

                  TABLE 1    ______________________________________    d-spacing (Å)                  Relative intensity (%)    ______________________________________    14.5          100    8.9           18    7.6           14    5.8           38    4.8           17    4.4           25    4.0           14    3.8           71    3.6           9    3.3           65    3.1           19    3.0           18    2.9           45    2.8           16    2.8           11    2.7           14    2.6           5    2.4           9    ______________________________________

Other minor signals at d-spacings of less than 15 Å (relative intensityof less than 5%) were also present. This diffraction can be assigned tothat of faujasite X.

The pore volume of the micropore volume of the calcined material wasdetermined from equilibrium N₂ adsorption capacity at different N₂partial pressures, according to ASTM standard method D 4365-85. Thecalcined material had a micropore pore volume of 0.25 cc/g.

The mesopore size distribution of the calcined material was determinedfrom equilibrium N₂ desorption isotherm, according to ASTM standardmethod D 4641-93. FIG. 1 shows the N₂ desorption isotherm for thecalcined material. As shown, the desorption isotherm has an inflectionpoint at P/P₀ equal to 0.55, which corresponds to the filling of a poresystem of 50 Å in average diameter. The sharp drop in the isothermaround this inflection point indicates a narrow pore size distribution.FIG. 2 is a plot of the derivative of the N₂ desorption volume as afunction of pore diameter, which further illustrates the narrow poresize distribution for the mesopores of between about 40 Å to about 60 Å.

The mesopore pore volume was determined according to ASTM standardmethod D 4641-93, and was found to be 0.12 cc/g.

EXAMPLE 2

This example illustrates the preparation of another material accordingto the present invention using faujasite X nuclei. A suspension offaujasite X nuclei was prepared as follows.

A suspension (Suspension A) was prepared by vigorously stirring amixture of 20.5 g of sodium silicate (29% wt SiO₂ ; 9.3% wt Na₂ O; 61.7%wt H₂ O) and 6.8 mL of a 13.4 M NaOH solution. A solution (Solution B)was prepared by dissolving 1.38 g of sodium aluminate (49.1% wt Al₂ O₃ ;27.2% Na₂ O, 23.7% H₂ O) into 8.2 mL of a 5.9 M solution of NaOH.Suspension A was added over Solution B, while stirring the latter. Afterthe addition was complete, stirring was continued for one more hour,resulting in a clear suspension of faujasite X nuclei having thefollowing composition:

    1 SiO.sub.2 :0.066 Al.sub.2 O.sub.3 :1.06 Na.sub.2 O:15.1 H.sub.2 O

This is suspension was aged at room temperature for 24 hours, afterwhich a solution of 7.98 g of cetyltrimethylammonium bromide (CTAB) in10 g of water was added, resulting in a suspension having the followingcomposition:

    1 SiO.sub.2 :0.066 Al.sub.2 O.sub.3 :1.06 Na.sub.2 O:0.22 CTAB:21 H.sub.2 O

This suspension was aged for 24 hours at a temperature of 80° C., andthe resulting solid was washed, dried at 100° C. for 4 hours, and thencalcined at 500° C. for 6 hours in a flow of air.

The calcined product shows an x-ray diffraction pattern having the mainstrong signals as set forth below in Table 2:

                  TABLE 2    ______________________________________    d-spacing (Å)                  Relative intensity (%)    ______________________________________    14.5          100    8.9           21    7.6           13    5.8           32    4.8           16    4.4           20    4.0           12    3.8           69    3.6           7    3.3           66    3.1           16    3.0           17    2.9           49    2.8           19    2.8           12    2.7           15    2.4           6    ______________________________________

Other minor signals at d-spacings of less than 15 Å (relative intensityof less than 5%) were also present. As with the diffraction of Example1, this diffraction is characteristic of faujasite X.

The pore volume of the micropore volume of the calcined material wasdetermined as in Example 1. The calcined material had a micropore porevolume of 0.21 cc/g.

The mesopore size distribution of the calcined material was determinedfrom equilibrium N₂ desorption isotherm as set forth in Example 1. FIG.3 shows the N₂ desorption isotherm for the calcined material. As shown,the desorption isotherm has an inflection point at P/P₀ equal to 0.65,which corresponds to the filling of a pore system of 65 Å in averagediameter. The sharp drop in the isotherm around this inflection pointindicates a narrow pore size distribution. FIG. 4 is a plot of thederivative of the N₂ desorption volume as a function of pore diameter,which further illustrates the narrow pore size distribution for themesopores of between about 50 Å to about 70 Å.

The mesopore pore volume was determined according to ASTM standardmethod D 4641-93 as in Example 1, and was found to be 0.15 cc/g.

EXAMPLE 3

This example demonstrates the narrow pore size distribution in themesopores formed in material according to the invention compared tomaterial treated conventionally to obtain larger pore sizes.

The N₂ desorption isotherm of a commercial steam dealuminated zeolite Ywas determined according to ASTM standard method D 4222-91, with thedesorption isotherm being plotted as set forth in FIG. 5, with thederivative of N₂ desorption volume being plotted versus pore diameterfor the commercial sample in FIG. 6.

Comparing FIGS. 1, 3 and 5, it is apparent that the material preparedaccording to the present invention illustrates sharp inflection pointsin the isotherm between relative pressures of 0.05 and 0.8, while thecommercial sample shows a gradual increase over the same range. Thisdifference indicates that the material of the present invention has anarrow distribution of pore diameters in the 15 to 100 Å range, whilethe commercial material has pore diameters with a wide distribution ofsizes falling mainly in the 100 to 2000 Å range.

It should be readily apparent that a material and process for preparingsame have been provided which advantageously result in a microporousmolecular sieve material which also has a narrow pore size distributionof mesoporous pore volume as desired. The catalyst material of thepresent invention is particularly useful in treating feedstocks havinglarge organic molecules, and exhibits shape selectivity whichadvantageously provides enhanced conversion, transformation orpurification of the feedstock to be treated.

EXAMPLE 4

This example demonstrates the preparation of a material with a narrowdistribution of mesopores using dense nuclei of an aluminophosphate inaccordance with the process of the present invention.

Initially, a suspension of dense aluminophosphate nuclei in water wasprepared as follows. A suspension (Suspension A) was formed byvigorously stirring a mixture of 3.52 g of aluminum hydroxide Al(OH)₃ !and 50 mL of concentrated hydrochloric acid (HCl, 37% wt). A solution(Solution B) was prepared by dissolving 4.02 g of disodium hydrogenphosphate-7-hydrate, (Na₂ HPO₄ --7H₂ O, 99.9% wt) into 48.5 mL ofconcentrated hydrochloric acid (HCl, 37% wt). Another solution (SolutionC) was prepared by dissolving 5.28 g of para-nonyl phenol ethoxylatedwith fifteen moles of ethylene oxide per mole of alkylphenol(C9H19--Ph--O--(CH2--CH2--O)14--CH2--CH2--OH, where Ph is phenyl group)in 298 g of water. Suspension A and Solution B were added over SolutionC, while stirring the latter. After the addition was complete, stirringwas continue for 15 more minutes, resulting in a suspension of variscitenuclei having the following composition:

    1 Al.sub.2 O.sub.3 :0.3 P.sub.2 O.sub.5 :1 HCl:0.12 C.sub.9 H.sub.19 (EO).sub.15 :16.6 H.sub.2 O

This suspension was aged at room temperature for 3 days, after which 150mL of NaOH (8 N) were added, resulting in a suspension having thefollowing composition:

    1 Al.sub.2 O.sub.3 :0.3 P.sub.2 O.sub.5 :1 HCl:0.12 C.sub.9 H.sub.19 (EO).sub.15 :0.47 Na20:22.9 H.sub.2 O

This suspension was aged for 3 days at a temperature of 60° C., and theresulting solid was washed, dried at 100° C. for 4 hours, and thencalcined at 500° C. for 6 hours in a flow of air.

The mesopore size distribution of the calcined material was determinedfrom equilibrium N₂ desorption isotherm, according to ASTM StandardPractice D 4641-93. FIG. 7 shows the N₂ desorption isotherm for thecalcined material. As shown, the desorption isotherm has an inflectionpoint at P/P₀ equal to 0.45, which corresponds to the filling of a poresystem of 35 Å in average diameter. The sharp drop in the isothermaround this inflection point indicates a narrow pore size distribution.FIG. 8 is a plot of the derivative of the N₂ desorption volume as afunction of pore diameter, which further illustrates the narrow poresize distribution for the mesopores of 35 Å.

The mesopore pore volume was determined according to ASTM StandardMethod D 4641-93, and was found to be 0.24 cc/g.

This invention may be embodied in other forms or carried out in otherways without departing from the spirit or essential characteristicsthereof. The present embodiment is therefore to be considered as in allrespects illustrative and not restrictive, the scope of the inventionbeing indicated by the appended claims, and all changes which comewithin the meaning and range of equivalency are intended to be embracedtherein.

What is claimed is:
 1. A process for preparing a crystalline molecularsieve material selected from the group consisting of zeolite,metalosilicate, aluminophosphate, metaloaluminophosphate,silicoaluminophosphate, metalosilicoaluminophosphate and mixturesthereof, comprising the steps of:providing a suspension of nuclei of acrystalline molecular sieve material in an aqueous media; mixing thesuspension with a water soluble organic compound to provide a mixture ofthe nuclei and micelles of the organic compound in solution; inducingthe nuclei around the micelles of the organic compound so as to producea solid material having the organic compound dispersed therein;extracting the organic compound from the solid material to provide acrystalline molecular sieve material having a micropore volume greaterthan or equal to about 0.15 cc/g distributed in channels about 3 toabout 15 Å in average diameter, and having a mesopore volume of at leastabout 0.1 cc/g distributed in channels about 20 Å to about 100 Å inaverage diameter.
 2. A process according to claim 1, wherein the organiccompound is selected from the group consisting of cationic surfactant,anionic surfactant, non-ionic surfactant, amphoteric surfactant andmixtures thereof.
 3. A process according to claim 2, wherein the organiccompound is selected from the group consisting of quaternary ammoniumsalt, ethoxylated alcohol, ethoxylated alkyl alkylphenol, ethoxylatedacid, fatty acid alkanolamides, ethoxylated alkanolamides, ethoxylatedamine, amine oxide, derivative of saccharaide, polyalcohol,alkylbenzesulfonate, alkyl sulfate, alkanesulfonate, hydroxyalkylsulfonate, alpha-olefinsulfonate, alkyl ether sulfate, petroleumsulfonate, phosphate ester, soap, acylated amino acid, carboxybetaine,amino-acid, lecithin and mixtures thereof.
 4. A process according toclaim 1, wherein the inducing step is carried out at a temperature ofbetween about 20° C. to about 100° C. for a period of time of at leastabout 10 minutes.
 5. A process according to claim 1, wherein theconcentration of the organic compound is higher than the criticalmicellar concentration and lower than a liquid crystal concentration. 6.A process according to claim 1, wherein the nuclei of microporouscrystalline molecular sieve material are selected from the groupconsisting of nuclei of zeolite, metalosilicate and mixtures thereof,wherein the organic compound is a cationic surfactant, and wherein themixture of the nuclei and the organic compound in solution has a pHgreater than or equal to about 7, and wherein the inducing aggregationstep is carried out at a temperature of between about 20° C. to about100° C. for a period of time of at least about 10 minutes.
 7. A processaccording to claim 6, wherein the nuclei of microporous crystallinemolecular sieve material comprises faujasite zeolite nuclei.
 8. Aprocess according to claim 1, wherein the nuclei of microporouscrystalline molecular sieve material are selected from the groupconsisting of nuclei of aluminophosphate, metaloaluminophosphate,silicoaluminophosphate, metalosilicoaluminophosphate and mixturesthereof, wherein the organic compound is an anionic surfactant, andwherein the mixture of the nuclei and the organic compound in solutionhas a pH less than or equal to about 5, and wherein the inducingaggregation step is carried out at a temperature of between about 20° C.to about 100° C. for a period of time of at least about 10 minutes.
 9. Aprocess according to claim 1, wherein the step of inducing is carriedout in the presence of a binder.
 10. A process according to claim 9,wherein the binder is selected from the group consisting of colloidalsuspensions of silica, alumina, silica-alumina, magnesia, zirconia,titania and mixtures thereof.
 11. A process according to claim 1,further comprising the step of selecting the nuclei, the organiccompound and synthesis conditions so as to promote interaction betweenthe nuclei and the organic compound, whereby the inducing step resultsin aggregation of the nuclei around micelles of the organic compound.